Method for treating styrene



Patented July 16, 1946 UNITED STATES PATENT OFFICE METHOD FOR TREATINGSTYRENE Laszlo Ai'ier, South Orange, N. J.

No Drawing. Application October 12, 1942,

Serial No. 461,798

7 Claims.

GENERAL FIELD or INVENTION AND STATEMENT or OBJECTS having a boilingpoint at 145 C. to 146 C. It is a natural ingredient of storax (a kindof balsam), and is made synthetically, either by slow distillation ofcinnamic acid, or by passing a mixture of benzene vapor and ethylenethrough a red hot tube. This material, boiling at about 145 (3., hascome to be known as monomeric" styrene.

Monomeric styrene has many industrial applications, such, for instance,as for making resins, and for making thermo-plastic and also infusiblepolymers. The products resulting from heat treatment of monomericstyrene are useful in many different physical forms, for instance, inliquid form, or in paste-like or rubber-like forms, or in the form oftough solids, and also in the form of friable glass-like materials.

Broadly stated, the present invention has reference to the modificationof the characteristics and properties of monomeric styrene (vinylbenzene), so as to better fit the heat-treated material for various ofthe foregoing and other industrial purposes and applications. Brieflystated, the process of the invention involves heating the styrene withcertain modifying agents, and notably with polar compounds of quite awide variety of different types, capable of influencing the propertiesof styrene, and thereby enabling the production of modified styreneproducts having many different and new chemical and/or physicaliaracteristics.

It has long been known that mere heating of styrene will change thephysical consistency thereof. The present invention, however,contemplates further changes in properties, i. e., changes in additionto those brought about by mere heating. Thus, for example, the inventioncontemplates employment of certain modifying agents capable of altering,for instance, accelerating or retarding, the effect which a particularheat treatment would otherwise produce. Moreover, employment of variousof the modifying agents introduces other changes in the properties whichdo not occur by heating'alone.

In referring to changes of the foregoing type (and others) and in makingcomparisonsof the modified and heat treated styrene products withproducts not treated with modifying agents, it is to be understood thatthe statements regarding changes and comparisons are always made on thebasis of a relation between the product treated with a modifying agentand a product treated in exactly the same manner (heating, etc.) butwithout a modifying agent. The latter is often herein referred to as ablank or control experiment.

As is mentioned in my copending application above referred to, and alsoin others referred to hereinafter, I believe styrene to be anorganicisocolloid, i. e., a colloidal system in which the dispersed phase andthe dispersion medium are both of the same chemical composition thoughpresent in different physical states.

By the modification process of the present invention, I believe therelative proportions of dispersed phase and dispersion medium arealtered,-

thereby altering the properties, and notably the physical consistency ofthe product. In fact, I consider styrene as being one of the bestexamples of organic isocolloids in which the relation of the dispersedphase and dispersion medium may be altered by treatment in various ways.

The modifications in physical consistency which may be brought about bythe employment of various of the polar compounds contemplated,

for use as modifying agents is, in many cases, extremely pronounced, sothat even when employing relativel low viscosity styrene as startingmaterial, it is possible, by employment of certain modifying agents, tobring about an extremely rapid and also extremely extensive degree ofsolidification (when at room temperature). In fact, it is possible bythis change in relation between the dispersed phase and dispersionmedium and/or by aggregation to readily produce a product almost ofglass-like consistency.

On the other hand, by appropriate selection of certain other modifyingagents, it is also possible to retard the tendency to solidify whichaccompanies heating at certain temperatures, and in fact, even toproduce products of liquid consistency (when at room temperature),though such products may be altered with respect to other properties.This-type of modification may for convenience be considered asliquefaction, in

contrast to the modification brought about by other agents tending topromote solidification.

I believe also that by the process of the present invention, the size ofthe micelles of the disperse phase may also be changed.

THE MODIFYING AGENT As is mentioned in my copending application aboveidentified, I believe that the colloidal system of organic isocolloidsmay be modified by means of modifying agents. According to theinvention, such modifying agents are polar compounds in general. Bypolar compounds I mean compounds having polarity in the molecule, thusincluding electrolytes. Examples are given below.

Polar compounds are of many different classes, many of which are definedin my copending ap plication above mentioned (and also in othersreferred to hereinafter). The type of modification secured by variousgroups of modifying agents and even by individual agents, may be quitedifferent, many agents and groups producing results which are quitedistinctive, although as before mentioned, I believe the polar compoundsare capable of influencing the colloidal system of the styrene, invarious of the respects already mentioned, and possibly also in otherrespects.

As a broad general classification, the polar compounds may be dividedinto two groups, one of which tends to promote solidification of thestyrene, and the other of which tends to retard solidifying which wouldnormally occur by certain types of treatment (for instance, heatingunder given conditions). It is here again mentioned that thesecomparisons are based on the relation. to a treatment of styrene underthe same condi tions but without employing the modifying agent.

The first classification of modifying agents is particularly useful ininstances where it is desired to secure hard products, such asglass-like products. where it is desirable to employ agents tending topromote solidification.

On the other hand, the second classification is of especial importancefor certain other purposes, particularly where toughness in the productis desired, as for example, in molding powders for injection moldingpurposes. This second classification is also of importance where thestyrene prodnot is to be employed in coating compositions and the likeand in instances where co-polymerization or co-aggregation is desiredbetween the styrene and other unsaturated organic isocolloids, and alsowhere large batches are to be treated, in which event retarding the rateof solidification aids in securing uniformity of treatment through themass of the batch.

At least many of the metal salts are polar compounds belonging to thefirst classification. Acid salts, and especially materials containing ordeveloping S02, usually display a strong solidifying action. Many metalhalides, (halogen salts) also promote solidification. As an example ofone specific material, it may be mentioned that sodium bisulphiteextensively promotes solidification.

In the second classification are at least many of the organic sulphoandhalo-compounds, and of the organic amines. A specific example of thisgroup is benzidine base.

More particularly, the modifying agents include organic and inorganicacids, the salts of such acids, and metallic derivatives of organiccompounds (organic metal compounds) separately or mixed.

Acidic polar compounds, either organic or inorganic compounds, areeffective groups of modifying agents.

Compounds containing the following cations or anions, or both, areadvantageous:

There are, of course, many other uses As cations: As anions:

Ammonium Naphthalene sulphomc Sodium (acid) Potassium Carbonic (acid)Lithium Tartaric (acid) Strontium Oxalic (ac d) Calcium Acetic (acid)Barium Formic (acid) Magnesium Citric (acld) I Iron (ferric and ferrous)Hydrochloric (ac d) Cobalt Hydrobrpmic (acid) Aluminum Hydriodic (acid)Lead Sulphuric (acid) Antimony Sulphurous (acid) ManganeseHydrosulphurous (acid) Tin (stannic and stan- Hydrosulphuric (acid)nous) Thiosulphuric (acid) Cadmium Nitric (acid) Bismuth Nitrous (acld)Zine Boric (acid) Organic ammonium ions. Phosphoric (acid) etc.Hydrocyamc (acid) .verted by the addition of one or more hydrogen atoms,or water molecules, or merely by the application of heat, into aninorganic acid, in-- cluding carbonic acid as inorganic.) This group ofpolar compounds may be represented by the following generic formula RXnwherein R represents the inorganic acidic residue, and X represents theinorganic acidic residue, the n being 1-5. The acidic inorganic groupsmay be nitro, halogen, sulphur-containing radicles, carboxyl, etc., andone or more such groups may be present in the molecule and attached tothe organic residue.

Organic halogen compounds constitute an advantageous class, botharomatic and aliphatic, containing chlorine, iodine, bromine, etc., thefollowing being typical and illustrative of this class:

o-Dichlorobenzene p-Dichlorobenzene Trichlorobenzene Naphthalenetetrachloride Naphthalene trichloride Naphthalene hexachlorideNaphthalene monochloride Nitro-chlorobenzenes, ortho, meta and paraNitro-dichlorobenzenes Chloro-dinitrobenzenes MonochlorobenzeneChlorinated diphenyl Pinene hydrochloride l-chloro-o-anisidinep-Nitro-chloro-benzene Triphenyl-chloro-methane Benzyl chloride Benzoylchloride Acetyl chloride Acetyl bromide Phthaloyl chlorideTrichloroacetic acid Monochloroacetic acid Chloral hydrate Iodoform Thehalogen compounds listed ante and other halogenated aryl and aliphaticcompounds, including acyl chlorides, chloro -acids, hydrochloride salts.etc. may be used in the practice of the present invention. From the listgiven it will be seen that such halogenated compounds may also containother substituents in addition to the halogen, such as hydroxy. amino,nitro, alkyl, aryl and other groups. Accordingly. such polar compoundsmay also be classified in the other groupings of these modifying agents.

In. fact, nitro compounds per se are useful and advantageous in thepractice of the present invention. And nitro organic compounds areanother advantageous class of organic polar compounds. The followingnitr'o compounds are typi cal and illustrative of this class:

Nitrobenzene o-Nitrophenol p-Nitrophenol DinitrobenzeneNitro-chloro-benzene Dinitro-chlorobenzene Dinitroanilinep-Nitro-acetanilide Nitrocresol carbonate m-Nitroaniline hydrochlorideEthyl thioether of Z-nitrobenzene Ethyl thioether of 2:4 dim'trobenzeneEthyl thioether of nitro-aminohenzene 2 z l-dinitrobenzeneNitro-aminobenzene These illustrate the various general types of nitrocom-pounds which may be used in addition to the nitro compounds shown inthe other classifica tion of these polar compounds.

Another advantageous class of modifying agents or polar compounds arethe aromatic sulphonic acids, together with their salts, esters andhalides. Of these the sulphonic acids and the sulphonyl chlorides areparticularly useful here.

These polar compounds may be represented by the following genericformula R-SOn--Y, wherein R, represents an aryl nucleus, Y representshydrogen, chlorine or an alkyl group or 'a metal and n is 0 to 4.Typical examples of such compounds are the following compounds:

Benzene sulphonic acid p-Toluene sulphonic acid 2:5 dichlorobenzenesulphonic acid m-Xylidine sulphonic acid pToluidine-m-sulphonlc acidNaphthalene 2:6 sulphonic acid Beta-naphthol 1:5 sulphonic acidBeta-naphthol 3:6:8 sulphonic acid Beta-naphthylamine 3:6:8 trisulphonicacid 2:1 naphthylamine sulphonic acid 2:6 naphthylamine sulphonic acid2-phenylamine-8-naphthol-6-sulphonic acid Methyl-p-toluene sulphonateEthyl chlorosulphonate Benzene sulphonyl chloride p -Toluene sulphonylchloride Naphthalene-l-sulphonyl chloride Dimethyl sulphateDiaminodihydroxy anthraquinone disulphonic acid Metal salts of suchsulphonic acids, such as the sodium salts, are useful in the presentinvention.

A still further class of polar compounds are 6 the organic esters ofinorganic acids, both aryl and alkyl esters, for instance, thefollowing:

Triphenyl phosphate 'I'ricresyl phosphate and other alkyl-phenylphosphates Nitrocresyl carbonate Ethyl chlorosulphonate Dimethylsulphate In addition to these, other alkyl and aryl esters of inorganicacids such as borates, phosphates, phosphites, sulphides, sulphates,thiocyanates, etc., may be used; for instance, propyl, butyl, amyl andiso-alkyl esters. Likewise, esters of various aliphatic alcohols andphenols with organic acids may be used.

Still another class of modifying agents or polar compounds useful inthis invention, are the inorganic salts of organic bases, of which thefollowing compounds are illustrative:

Diphenylamine hydrochloride Diphenylamine hydrobromide m-Nitroanilinehydrochloride richloroaniline hydrochloride Diphenyl amine sulphateDiarninodiphenyl sulphate Aniline sulphate Amino-azo-benzene sulphate4:4 diamino-diphenyl sulphide Aniline hydrochloride Several of the abovecompounds in addition to being salts, also contain other groups whichimpart polarity to the compound, such as nitro, amino and halogengroups. Compounds containing such groups are useful. per se, as statedante.

As examples illustrative of organic salts of organic acids, there may bementioned diphenylamine trichloroaoetate and methyl p-toluenesulp'oonate. Other wholly organic salts may be used. For instance, thealkyl and aryl esters of the various organic acids mentioned ante, suchas tartrates, oxalates, acetates, formates, thiccyanates. salicylates,etc., may be used in the present invention. These are illustrative ofthe esters of monoand di-basic acids which may be employed.

Likewise, alkyl and phenyl esters of other aliphatic and aromaticcarboxylic acids, both monoand di-basic acids, such as phthalates,benzoates, acetates, abietates, oleates, laurates, palmitates,rioinoleates, etc., may be used. Both the monoand di-esters of di-basicacids are useful here. Likewise mixed alkyl and aryl esters andalkylated phenyl esters can be employed in some cases. Typical examplesare as follows:

Dibutl phthalate Mono-butyl phthalate Di-ethyl phthalate Ethyl butylphthalate Di-phenyl phthalate Ethyl-phenyl tartrate Methyl abietateEthyl abietate Di-ethyl succinate Phenyl thiocyanate Ethyl malonateDiethylammonium diethyldithiocarbamate Ethyl salicylate Methylsalicylate Ethyl ether of ethyl salicylate Butyl ether of ethylricinoleate phur acids.

That is, ether-ester and acid esters may be also employed here. Further,thioethers such as diaminodiphenyl sulphide, may also be used; theybeing so to speak organic esters of organic mercaptans (RrS-H) which aremore or less sul- Other useful organicsulphides are diphenyl sulphide,ethyl phenyl sulphide and the alkyl thioethers of nitrobenzenes, such asthe ethyl thioether of 2-nitrobenzene or of 2:4 dinitrobenzene. That is,the phenyl group of such sulphides or thioethers may be furthersubstituted with groups such as amino, nitro, etc.; these groupsincreasing the polarity of the molecule.

Many of the polar compounds illustrated ante in the variousclassifications also contain amine or amino groups. Amines having arelatively high molecular weight are advantageous.

In the present invention, compounds containing primary, secondary ortertiary amine groups and containing one or more of such amine groupsmay be used as the modifying agent; those containing two such groupsbeing advantageous.

One of the advantages of the amines as modifving agents is that they arerelatively easier to dissolve or disperse in some organic isocolloids inorder to modify them.

The amines may be used by themselves or in conjunction with othermodifying agents. For instance, the amines may be used in conjunctionwith polar compounds comprising within the molecule an acidic inorganicresidue and an organic residue such as given ante. Again, it issometimes advantageous to use as the modifying agent. an organic polarcompound containing both an amine group and an acidic residue, such asthe aromatic amino sulphonic acidsand other compounds of that type shownante.

In addition to the amines, I may also use other organic bases asmodifying agents in the present processes, for instance. napthols.henols, etc. A wide range of organic bases may be used, according to thetype of modified product desired.

The direct use of organic bases, such as andhydroxy compounds, as themodifying agent. may be of advantage. However, in most embodiments ofthe present invention, such organic bases are used in conjunction withother modifying agents, they being employed to give an additionalmodification in the properties of the products obtained. The organicbases may be used here in conjunction with metal salts, acids, acidchlorides (acyl chlorides), etc. As stated ante, such polar compoundsare advantageous modifying agents when used alone.

In fact, the acids are an important class of polar compounds and may beused alone as the modifying agent in the practice of the presentinvention. Certain of the advantageous acids, particularly the organicacids, have been de scribed ante, although the inorganic acids are alsouseful.

In connection with the salts and esters, I mention many acids and theseare suitable for use here in the form of the free acid as well as in theform of metal salts and esters. As mentioned ante, acid salts and acidesters may be used and these so to speak are partly neutralized acids;that is, they are of acid character. Also the anhydrides and acidchlorides of these acids are useful here as the modifying agent. Asshown ante, the metal salts of these acids may be used as the polarcompound, here.

Examples of metal salts, both neutraland acid Ammonium iodide Cadmiumiodide Zinc bromide Barium thiocyanate Potassium thiocyanate Ammoniumchloride Magnesium chloride Magnesium sulphate Sodium sulphate Sodiumhydrogen sulphate Di-sodium hydrogen phosphate Sodium bisulphite Sodiumsulphite Lithium sulphite Lithium carbonate Zinc carbonate Sodiumsulphide Barium sulphide Lead chromate Potassium dichromate Cadmiumsulphide. Sodium bicarbonate Tin carbonate Tin sulphite Tin sulphide.

Tin chloride (stannous and stannic) Antimony sulphide Zinc sulphideBarium sulphide Barium carbonate Calcium sulphite Strontium sulphiteMagnesium sulphite Barium sulphite Lead sulphite Cadmium sulphiteMercuric sulphate It will be noted that, almost without exception, thepolar compounds listed or described herein are distinguished by thepresence in the molecule of two or more dissimilar atoms, at least oneof which atoms is a non-metal-the non-metals being defined as elementswhose oxides react with water to form acids. (See, for instance, Holmes,General Chemistry, 1923 Edition, pages 19 and 67.) Of this generalclass, nitrogen, sulfur and the halogens are outstanding exponents.

TREATMENT CONDITIONS Various of the treatment conditions will, ofcourse, be different, depending upon th modifying agent selected and thecharacter of the product desired.

One of the most important considerations here to be noted is thatthorough dispersion of the modifying agent in the colloidal system ofthe styrene is of importance. The modifying agents may be ground ormilled, for instance, on a paint mill or the like, together with atleast a portion of the styrene as an aid in securing dispersion.Moreover, agitation may be employed to this same end.

customarily, however, application of heat is of importance in securingthorough dispersion and effective modification of the styrene. Thetemperature of heating is desirably above room temperature but shouldnot be above the distillation point (boiling point) or decompositionpoint. This, in fact, is true in general of treatment of iso-colloids asis mentioned in my copending applications elsewhere referred to herein.

Since the boiling point of styrene is about 146 0., the treatmenttemperatur should not exceed that figure, when initially treatingstyrene. A range from about 100 C. to about 146C. is effective for mostmodifications of styrene.

It is to be understood, however, that various physical properties andcharacteristics of styrene may be modified during the course oftreatment, including the .boiling or decompositio point itself, and inview of this in instances where the boiling point is increased by virtueof the process, subsequent continued treatment, or treatment of thestyrene in successive stages may be accomplished at temperatures higherthan 146 C. Thus, as will appear in examples given herebelow, in thelatter Stages of multi-stage treatment of styrene, the treatmenttemperature was carried up to as high as 200 0., and even somewhathigher temperatures may be employed, depending upon the condition of thematerial at the time. This may be of importance, for instance, where thematerial is being treated with polar compounds tending to retardsolidification of the product.

As an additional point in connection with temperatures, it may be notedthat the treatment is applicable where the styrene is being modified inthe presence of other materials. In this event the mixture may have ahigher boiling point than that of styrene, because of the presence ofother materials, and the temperaturemay under such circumstances also beabove the boiling point of the styrene itself.

Another point to be kept in mind in connection with temperature is thatvariations in temperatures maybe desirable in accordance with whether ornot the styrene is being treated in the presence or in the absence ofsolvents. Where solvents are employed, the temperature may be determinedat least in part by the nature of the solvent itself. On the other hand,in the absence of solvents a temperature of at least 100 C. is usuallydesirable.

As a general guide it may be said that the temperature treatment shouldnot exceed the decomposition point or boilin point of the reactionmixture, or of that major ingredient having the lowest boiling ordecomposition point. Particularly advantageous results are frequentlysecured by employing a temperature close to the boiling or decompositionpoint.

The reaction may take place under refluxing and this may be useful for anumber of purposes, including promotion of thorough dispersion of themodifying agent. In such refluxing process, a solvent may be used eitherfor the modifying agent or for the styrene or for both.

The time of treatment may be varied over a very broad range, dependingupon the nature of the modification desired and upon other conditions ofthe process, including the modifying agent being employed. As a generalguide from about hour up to about or hours is effective.

With regard to the percentageof modifying agent, here again considerablevariation is possible, dependin upon the results desired. Anywhere uponto about 10% of the modifying agent is usually found quite effective,for instance, from about a trace such as .05% or .5% up to about 10%.For many purposes from 1% or 2% up to 10% constitutes the most eifectiverange.

The treatment may be carried out under varying conditions of pressureand atmosphere, for instance, under vacuum, at atmospheric pressure orat higher than atmospheric pressure. 'Other variations in this regardare mentioned more fully hereinafter.

EXAMPLES In a series of comparative examples below, a number oftreatment conditions were maintained the same in each case. For thepurpose of conductin this series, a constant temperature glycerine bathwas used for heating, the bath being thermostatically regulated tocontrol the temperature of the bath to within 1, plus or minus, of 122C. In each example a charge of styrene was placed in an Erlenmeyerflask, with a. thermometer in the charge and with a delivery tubeattached to the flask. In each case the treatment period was 6 hours.

In the several different examples diiferent modifying agents were used,the quantity of modifying agent being 5%.

In addition to the numbered examples discussed ;iust below, blankexperiments were also conducted in the same manner. One such blankexperiment, identified as Blank A, utilized a 250 gram. charge ofstyrene in a 500 ml. flask, this blank being made for purposes orcomparison with other examples employing the same size flask and thesame size charge. In treating Blank A, the temperature rose byexothermic reaction to 157 C. in 3 hours. The product of this blank (atroom temperature) was a plastic gel.

In another such blank experiment, identified Blank B, a gram charge ofstyrene was placed in a 250 ml. flask. This blank may be compared withvarious of the numbered examples employing a 250 ml. flask and a 100gram charge. In the treatment of Blank B, the material reached atemperature of 126 C. in 3 hours. The rise and decline in temperaturewas very gradual. 'ne product of this blank was a somewhat elasticgelatinous product of rubber-dike consistency at room temperature.

All statements made with regard to consistency of the products refer toconsistency when cooled to room temperature.

Example 1 A 250 gram charge of styrene was placed in a 500 ml. flask.Sodium bi'sulphite was used as the modifying agent, the agent firstbeing pulverized and then added to me charge. The temperature rose to156 0. within 4 hours, the approach to that temperature being gradualalthough the subsequent drop was very sharp. The product was a vitreoussolid showing no cold flow.

Example 2 A 250 gram charge of styrene was placed in a 500 ml. flask.Barium peroxide was pulverized and added to the styrene. In 3 hours thereaction mass reached a temperature of 147 C., both the approach to andthe recession from that temperature being gradual. The product was arubber-like solid, stiifer and more tenacious than the correspondingBlank A.

Example 3 A 100 gram charge of styrene was placed in a 250 ml. flask,together with 5% of pulverized anhydrous sodium sulphate. Thetemperature .Sponding control 'ro'seto 124 C. within hour, whichtemperature was maintained fairly uniformly for about 4 hours afterwhich the temperature dropped. The productwas' similar to thecorresponding control B but was harder and more in the nature of arubber-like plastic.

Example 4 A100 gram charge of styrene was placed in a 25011111. .flaskwith 5% of sodium bisulphate (sodium acid sulphate). A maximumtemperature. of. 127 C. was reached within 3 hours, with gradual riseand decline. The product was harder and more rubber-like and elasticthan the corre- Example 5 gram charge styrene was placed in a 250 ml.flask together with, 5% of benzidine base. The

temperature rose within 30 minutes to 126 C.

and showed a very gradual decline for the dura- ,tionof the experiment.The product was a soft pasty mass of brown color, containing partiallyundissolved modifying agent.

Example 6 100 gram charge of styrene was placed in a 250 ml. flask with5% salicylic acid. The temperature'rose to 125 C. in about 3 hours andshowed a gradual decline thereafter. The product was a paste-like masscontaining some undispersed m i yin Example 7 100 gram charge of styrenewas placed in a 250 ml. flask with 5% sodium bicarbonate. During thereaction'bubbling and gas evolution occurred and the temperature did notdeviate more than about 1 from 121 C. The product was a soft mass, themodifying agent apparently having been at least partially decomposed.

7 Example 8 .1160 grams of styrene were placed in a 250 ml. flash with5% chloral hydrate. The temperature rose to 120 C. within one hour whichwas maintained. to about the third hour of treatment, after .whichthetemperature declined 3 below the temperature of the thermostaticallycontrolled bath, (122 CI) The product was a viscous waterwhite liquid ofuniform appearance.

Examples 3 to 8 inclusive above are comparative, all being performedwith a 100 gram charge in a 250 ml. flask under the same conditions ofheating, time, etc. Comparison of the products of this group of examplesindicates that the sodium sulphate and the sodium bisulphate of Examples3 and 4 both displayed solidifying action, whereas benzidine base,salicylic acid, and chloral hydrate of Examples 5, 6 and 8, alldisplayed a liquefyingf action, this action being very strong in thecase of chloral hydrate.

Example 9 A 100 gram charge of styrene was placed in a 250 ml. flask;together with 5% of p-toluene sulphonic acid. A. maximum temperature of143 C. was reached within 20 minutes with rapid drop to 117 C., whichtemperature was maintained throughout the balance of the treatment. Theproduct was a soft brown paste having an opalescence and greenfluorescence.

Example 10 A 100 gram charge of styrene was placed in a 250 ml. flasktogetherwith 5% of diphenylamine.

The maximum temperature reached was 120 (3., this being attained inabout 3 hours. The increase to this temperature and the 'drop whichfollowed were both rapid. The average temperature of the treatment wasnoticeably below that of the heating bath. The product Was of a uniformbrown color and'was a slightly gelatinous paste, somewhat softer thanthe corresponding control B.

Example 11 A gram charge of styrene was placed in a 250 ml. flasktogether with 5% of anhydrous calcium chloride. The temperature roserapidly (within 20 minutes) to 123 C. and thereafter varied somewhatbetween about 118 C. to 121 C. for the duration of the treatment. Theproduct was an elastic rubber-like mass of harder consistency than thecorresponding control B.

Calcium chloride, Example 11, had a solidifying action, whereasp-toluene sulphonic acid and diphenylamine both displayed a liquefyingaction.

' Example 12 A 100 gram charge of styrene was placed in a 250 ml. flasktogether with 5% of trichloracetic acid. The temperature averaged about118 C. throughout the treatment. The product was a slightly viscousliquid.

Example 13 A 100 gram charge of styrene was placed in a 250 ml. flasktogether with 5% of p-nitrophenol. Two peak points appeared in thetemperature curve during heating, each at about 124 C., one occurring at1 /2 hours and the other at 5 hours. The product was a limpid liquidfrom which a portion of the modifying agent crystallized out.

Example 14 A 100 gram charge of styrene was placed in a 250 ml. flaskwith 5% of sodium hydroxide pellets. Maxi-mum temperature, of 128, wasnoted at 2 hours. The approach to the maximum was gradual and themaximum persisted for a period of about 1 hours, with-very gradual dropto 124 toward the end of the treatment. The product was harder andtougher than the corresponding control B. l

It will be noted that the trichloracetic acid and p-nitrophenol ofExamples 12 and 13 both displayed liquefying action, the latter beingmore pronounced than the former.

Example 15 Example 16 30 grams of styrene were placed in a glass beakerwith 20 grams of maleic anhydride. The beaker was heated in a water bathmaintained ataboil.

13 A vigorous reaction ensued, with a rapid rise in temperature to 160C. The product became quite solid, resembling a shellac-like resinousmaterial, which strongly adhered to the walls of the beaker.

Comparative series of Examples 17ct-e '1'4 and nitrogen. Such gases maybe either bubbled through the reaction mas or may be employed as ablanket upon the surface of the reaction mixture.

Light treatment and wave treatment of various types also influence thereaction, for instance, treatment with visible light, ultra violet lightor with electrical potential differences. Irradiation with oscillatingenergy of various wave lengths, X-rays, etc., may also be used.

Useful products may be made by emulsification of the modified styrene,or if desired, the modification process itself may be carried out onstyrene emulsions.

Many variations in process are possible, but these need not beconsidered in detail herein,

Consistency at 0 stone at room i kgf Agent reaction temperi g Colorature 17a B Blank G Vitreous s0lid Water-white. 17b 8 Chloral hydrate..-Viscous liquid- Hard tough solid Do. 170 9 p-Toluene-sulphonic acid Thinliquid. llg tly ge ed paste.-. Brown. 1711 l0 Diphenylamine Verydviscous11- Har t ug $0 D0.

qui 17 12 Trichloroacetic acid do Very hard tough SOhd. Yellow.

The product of Example 17b, when hot, can be drawn into a very longthread.

The product of Example 170 was very sticky when cool.

Comparative series of Examples 18a-e The products from Examples I'm-ewere then placed in an oven at 190 C. to 200 C., for 3 It may be notedthat the example above containing p-toluene-sulphonic acid (180) plainlyshowed that the modifying agent exerted a pronounced liquefying action.The product containing diphenylamine (18d) had increased toughness. Theother modifying agents varied other properties of the material.

VARIABLES AND SUPPLEMENTAL TREATMENT One point to be kept in mind underthis heading is that, as before mentioned, the styrene may be treatednot only by itself but also in combination with other materials,especially with organic isocolloids, for instance, with fatty oils,fatty and resin acids, etc. In addition, it is here pointed out that thetreatment is applicable not only to styrene itself but also tosubstituted styrene or styrene homologs, which behave in the same manneror in a similar manner to styrene.

The modifying agents may be used in combination or may be produced insitu in the reaction mixture.

In addition to treatment at various different pressures as above noted,the process of modification may also be carried out in the presence ofair or in the absence of air, or in the presence of certain other gases,such for instance, as CO2 since this subject is more fully considered inmy copending application 318,650 above mentioned, to which reference maybe bad if desired. In addition, a number of variables and supplementaltreatments, and also certain other features herein disclosed, are alsodisclosed in my earlier applications Serial Nos. 359,425, (now Patent2,213,944) 359,424 (now Patent 2,007,958) 446,172 (now Patent2,213,943); 273,159 (now Patent 1,985,230); and 143,786 (now Patent2,189,772).

I claim:

1. In the treatment of styrene to modify the properties thereof, theprocess which comprises incorporation in the styrene from 0.5% to 10% ofan inorganic salt, which is a member of the class consisting of sodiumbisulfite, sodium sulfate and sodium bisulfate, to promote thesolidification of the styrene which would tend to take place under thetreatment conditions applied, and heating the mixture above C. but notabove the point at which appreciable distillation or decomposition,whichever is lower, takes place under the conditions of the treatment,the heating being continued until the material produced is appreciablyharder than the same material heated to the same temperature and underthe same conditions but without a modifying agent.

2. The process in accordance with claim 1 in which the inorganic salt isin a substantiall dry state, when incorporated into the styrene.

3. In efiecting substantial changes in the physical consistency ofstyrene, the process which includes the application of heat to anintimate admixture of monomeric styrene with at least 1% but not morethan about 10% of a modifying agent, said agent being a metal salt of asulfurcontaining inorganic acid, and being a member of the classconsisting of sodium bisulfite, sodium sulfate and sodium bisuliate, inwhich process the mixture is maintained at the temperature above 100 C.but not above the distillation point of the reaction mixture for atleast a half hour, and until a product results which manifests aphysical consistency of increased hardness, when compared with thatproduced upon subjecting monomeric styrene to the same treatment but inthe absence of a modifying agent.

4. The process of claim 3 in which the percentage of the modifying agentused is 5%.

5. The process of claim 3 in which 5% sodium bisulfite was used as themodifying agent, the

agent first being pulverized and then added to the styrene, yielding aproduct which was a vitreous solid showing no cold flow.

6. The process of claim 3 in which 5% pulverized anhydrous sodiumsulfate was used as a modifying agent, yielding a rubber-like hardplastic product.

7. The process of claim 3 in which 5% sodium bisulfate was used as themodifying agent, yielding a product which was hard, rubber-like andelastic.

LAszLo AUER.

